Optical lenses are employed in a variety of devices for many purposes such as modifying focus and magnification. Among the devices in which optical lenses are of particular significance are cameras and imaging devices. With the continuing trend toward increased miniaturization, particularly in consumer electronics, the need to develop cameras and other imaging devices of reduced size is also increasing. This is particularly the case given that many small consumer electronics devices, such as wireless telephones, increasingly are equipped with cameras and/or other imaging devices.
Conventional optical lenses employed in cameras and imaging devices often lack compactness due to the number of lens components required by the lenses. For example, a compound refractive lens might require six different lens elements stacked in a serial manner to achieve desired optical characteristics. Conventional telescopic devices also are unsuitable for use as lenses in compact camera and other imaging devices. Even catadioptric devices, such as Schmidt-Cassegrain or Maksutov-Cassegrain devices, are too large for successful implementation in these applications. In particular, these various lenses and related devices are often excessively physically long (as viewed generally perpendicular to the direction of incident light), relative to the cameras and other imaging devices within which they are to be implemented. These lenses can be scaled down to reduce their length, but simply scaling the lens size reduces the total light energy collected and the optical resolution.
Given the need for cameras and other imaging devices of reduced size, and consequently the need for optical lenses of reduced size, it would be advantageous if new lens(es) and/or lens system(s) could be developed that were substantially more compact than conventional lenses. In particular, it would be advantageous if the new lens(es)/lens system(s) were significantly shorter in length (where length is the dimension that is generally parallel to the direction of incoming incident light) than conventional devices.